在达罗巴克生物合成中以太交联的SAM氧化酶的特征
Hai Nguyen1, I Dewa Made Kresna2, Nils Böhringer2,3
1Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, United States.
Journal of the American Chemical Society
|October 4, 2022
概括
在使用氧气的抗生素达洛巴丁A生物合成中,DarE酶形成了和C-C交叉链. 这种激进的S-adenosylmethionine酶挑战了这种酶类的厌氧功能范式.
科学领域:
- 生物化学
- 分子生物学
- 微生物学
背景情况:
- 达罗巴A是一种强效的抗生素,可对抗阴性细菌.
- 它的结构具有复杂的和C-C交叉链,其形成机制以前是未知的.
- 了解这些修饰是抗生素生物合成和药物开发的关键.
研究的目的:
- 阐明达洛巴A生物合成中的交叉链形成机制.
- 确定催化这些修饰的酶.
- 研究氧气在酶反应中的作用.
主要方法:
- 使用假定酶DarE进行体外酶检测.
- 质谱分析反应产物和同位素标记 (18O2,[18O]水).
- 用于将酶产物与成熟的达洛巴A结合的蛋白质溶解转化试验
主要成果:
- 激进的S-adenosylmethionine (SAM) 酶DarE催化了以太和C-C交叉链的形成.
- 这些反应依赖于氧气,氧气来源于O2,而不是水.
- DarE还可催化α,β脱,对前体peptide DarA进行三个不同的修饰.
- 该DarE产品可以通过蛋白质分解转化为达洛巴A,证实其在生物合成中的作用.
结论:
- DarE是一种新型的SAM激素酶,作为氧化酶,利用O2作为辅基.
- 这一发现扩大了已知的SAM激素酶的功能范围,超出了厌氧过程.
- 这项研究表明,激进的SAM酶可以在有氧环境中运作,挑战现有的范式.
- DarE的多方面催化活性为像达洛巴A这样的复杂RiPP的生物合成提供了洞察力.
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